| Server IP : 216.250.13.251 / Your IP : 216.73.216.164 Web Server : nginx/1.24.0 System : Linux gunay 6.8.0-134-generic #134-Ubuntu SMP PREEMPT_DYNAMIC Fri Jun 26 18:43:11 UTC 2026 x86_64 User : root ( 0) PHP Version : 7.4.33 Disable Function : pcntl_alarm,pcntl_fork,pcntl_waitpid,pcntl_wait,pcntl_wifexited,pcntl_wifstopped,pcntl_wifsignaled,pcntl_wifcontinued,pcntl_wexitstatus,pcntl_wtermsig,pcntl_wstopsig,pcntl_signal,pcntl_signal_get_handler,pcntl_signal_dispatch,pcntl_get_last_error,pcntl_strerror,pcntl_sigprocmask,pcntl_sigwaitinfo,pcntl_sigtimedwait,pcntl_exec,pcntl_getpriority,pcntl_setpriority,pcntl_async_signals,pcntl_unshare, MySQL : OFF | cURL : ON | WGET : ON | Perl : ON | Python : OFF | Sudo : ON | Pkexec : OFF Directory : /usr/share/doc/bpfcc-tools/examples/doc/ |
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Demonstrations of mysqld_qslower, the Linux eBPF/bcc version. mysqld_qslower traces queries served by a MySQL server, and prints those that exceed a latency (query time) threshold. By default a threshold of 1 ms is used. For example: # ./mysqld_qslower.py `pgrep -n mysqld` Tracing MySQL server queries for PID 14371 slower than 1 ms... TIME(s) PID MS QUERY 0.000000 18608 130.751 SELECT * FROM words WHERE word REGEXP '^bre.*n$' 2.921535 18608 130.590 SELECT * FROM words WHERE word REGEXP '^alex.*$' 4.603549 18608 24.164 SELECT COUNT(*) FROM words 9.733847 18608 130.936 SELECT count(*) AS count FROM words WHERE word REGEXP '^bre.*n$' 17.864776 18608 130.298 SELECT * FROM words WHERE word REGEXP '^bre.*n$' ORDER BY word This traced 5 queries, 4 of which took about 130 milliseconds. A pgrep command was used to specify the PID of mysqld. In this example, a lower threshold is used of 0.1 ms: # ./mysqld_qslower.py `pgrep -n mysqld` 0.1 Tracing MySQL server queries for PID 14371 slower than 0.1 ms... TIME(s) PID MS QUERY 0.000000 18608 24.201 SELECT COUNT(*) FROM words 13.242390 18608 130.378 SELECT * FROM words WHERE word REGEXP '^bre.*n$' 23.601751 18608 119.198 SELECT * FROM words WHERE word REGEXP '^zzzzzzzz$' It worked, but I'm not catching any faster queries in this example. Notice I added a query that searched for "zzzzzzzz": it returned an empty set, and ran 11 ms faster. A 0 ms threshold can be specified to trace all queries: # ./mysqld_qslower.py `pgrep -n mysqld` 0 Tracing MySQL server queries for PID 14371 slower than 0 ms... TIME(s) PID MS QUERY 0.000000 18608 0.105 select @@version_comment limit 1 2.049312 18608 0.099 SELECT DATABASE() 2.050666 18608 0.274 show databases 2.051040 18608 0.176 show tables 5.730044 18608 130.365 SELECT count(*) AS count FROM words WHERE word REGEXP '^bre.*n$' 9.273837 18608 0.096 select 1 9.553742 18608 0.059 select 1 9.986087 18608 0.080 select 1 This includes an initialization of a mysql client command, and selecting the database. I also added some "select 1;" queries, which do no work and return quickly. USAGE: # ./mysqld_qslower.py -h USAGE: mysqld_latency PID [min_ms]